Numerical Investigation on Laser-Assisted Flow Forming Process

2014 ◽  
Vol 620 ◽  
pp. 29-34
Author(s):  
Ling Yan Sun ◽  
Chao Yang
Keyword(s):  
Laser Beam ◽  
Three Dimensional ◽  
Reduction Rate ◽  
Intense Laser ◽  
Material Strength ◽  
Three Dimensional Model ◽  
Forming Process ◽  
Flow Forming ◽  
Heating Source ◽  
Heating And Cooling

Recent years laser-assisted manufacturing techniques are increasingly the focus of the automotive and aerospace industry due to cost price, low energy efficiency and safety. Among these techniques is laser-assisted flow forming process that combines laser beam technology with conventional flow forming process. During forming the material undergoes a rapidly heating and cooling cycles with the irradiative action of the laser beam, which is quite different from the traditional process. A transient three-dimensional model was developed to investigate the influence of laser irradiation on the forming process, in which a user-defined function was created to overcome the problem of a moving Gaussian heating source. The result indicates that a ring-shaped temperature field is acquired when the heating source scans workpiece along a thread; the deformation area on the workpiece during forming is extensively and continuously heated by intense laser radiation and the thermally induced loss of material strength significantly increases the formability concerning the achievable material reduction rate and tool service life; the possibility of accuracy improvement by laser assistance has been investigated and an accuracy error decreases 10%-28.5%.

Numerical Simulation of Convective-Radiative Heat Transfer in a Solar Chimney

2014 ◽  
Author(s):  
Bernardo Buonomo ◽  
Oronzio Manca ◽  
Sergio Nardini ◽  
Gianluca Tartaglione
Keyword(s):  
Kinetic Energy ◽  
Electrical Power ◽  
Vertical Wall ◽  
Three Dimensional ◽  
Temperature Fields ◽  
Three Dimensional Model ◽  
Solar Chimney ◽  
Ansys Fluent ◽  
Heating And Cooling ◽  
Air Stream

Solar chimney is a new method to produce electrical power. It employs solar radiation to raise the temperature of the air and the buoyancy of warm air to accelerate the air stream flowing through the system. By converting thermal energy into the kinetic energy of air movement, solar chimneys have a number of different applications such as ventilation, passive solar heating and cooling of buildings, solar-energy drying, and power generation. Moreover, it can be employed as an energy conversion system from solar to mechanical. A component, such as a turbine or piezoelectric component, set in the path of the air current, converts the kinetic energy of the flowing air into electricity. In this paper, a numerical investigation on a prototypal solar chimney system integrated in a south facade of a building is presented. The chimney is 4.0 m high, 1.5 m wide whereas the thickness is 0.20 m for the vertical parallel walls configuration and at the inlet 0.34 m and at the outlet 0.20 m for convergent configuration. The chimney consists of a converging channel with one vertical wall and one inclined of 2°. The analysis is carried out on a three-dimensional model in airflow and the governing equations are given in terms of k-ε turbulence model. The problem is solved by means of the commercial code Ansys-Fluent. The numerical analysis was intended to examine the effect of the solar chimney’s height and spacing. Further, comparison between radiative and non-radiative model is examined and discussed. Results are given in terms of wall temperature distributions, air velocity and temperature fields and transversal profiles for a uniform wall heat flux on the vertical wall equal to 300 W/m2. Thermal and fluid dynamics behaviors are evaluated in order to have some indications to improve the energy efficiency of the system.

scholarly journals Numerical Simulation and Experimental Confirmation of a Bimetallic Pipe Forming Process

Materials ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 3561
Author(s):  
Zhiqiang Dong ◽  
Zhenzhen Xu ◽  
Wenke Wang ◽  
Zongyue Bi ◽  
Jianxun Zhang
Keyword(s):  
Stress Distribution ◽  
Three Dimensional ◽  
Good Choice ◽  
Image Correlation ◽  
Residual Tensile Stress ◽  
Three Dimensional Model ◽  
Forming Process ◽  
Corrosion Failure ◽  
Cold Forming ◽  
Bimetallic Pipe

Most oil and gas is transported by pipeline, and corrosion causes a great threat to the service life of the pipeline; bimetallic pipe, which combines the advantages of good mechanical properties, good corrosion resistance, and relatively low price, is a good choice for high-pressure and corrosion-resistant pipe, but its manufacturing process and stress distribution are more complex than single metal pipe. JCO is a widely used cold forming method for pipes which is named by the shape of the plate in the forming process, i.e. J-shape, C-shape and O-shape, and the forming process is an important parameter that determines the level of imperfections and residual stresses in a pipe, and residual tensile stress will accelerate corrosion failure of the pipe. In this study, the three-dimensional (3D) finite element method (FEM) is used to simulate the pre-bending and JCO forming process of a 2205/X65 bimetallic pipe. The model and the simulated results are validated by digital image correlation (DIC) experimental and the opening width of the formed pipe billet, respectively. The influence factors of the stresses are studied. Further, a two-dimensional (2D) model is established to study the characteristics of bimetallic plate bending and the stress distribution at the interface of different materials, and the results are compared with that of three-dimensional model.

Numerical and Experimental Analysis for Large Radius Deformation of Stainless Steels by Laser Forming Process

2005 ◽  
Author(s):  
J. Pennuto ◽  
J. Choi
Keyword(s):  
Experimental Data ◽  
Phase Transformation ◽  
Experimental Testing ◽  
Three Dimensional ◽  
Laser Forming ◽  
Bend Angle ◽  
Large Radius ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Forming Process

In an effort to develop a process free of dedicated tooling, this research seeks to study large radius deformation by laser forming. Experimental testing was conducted to determine how the laser parameters affect the single pass output bend angle as well as the additive bend angle from successive parallel, evenly spaced laser irradiations. As an extension of the previous developments, this work seeks to develop a three-dimensional model to simulate the multi-scan laser process. It is of interest to determine how sophisticated a three-dimensional case is required for sufficient agreement to experimental data. The simulated results of bending angle are compared with experimental data and suggestions for future study include the implementation of phase transformation and microstructure data within the model to account for stress development resulting from phase transformation and grain growth.

Numerical Simulation on Drawing Deep of Cylindrical Pieces Based on Dynaform

2014 ◽  
Vol 684 ◽  
pp. 252-258 ◽  
Author(s):  
Jun Hong Wang ◽  
Xu Dong Bao ◽  
Hai Mei Feng ◽  
Chang Du
Keyword(s):  
Numerical Simulation ◽  
Three Dimensional ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Forming Process ◽  
Minimum Thickness ◽  
Optimum Parameters ◽  
Design And Manufacture ◽  
The Impact

Abstract: The design and manufacture of mold often rely on the experience of the designers, which led to the fact that the mold needs to be repeatedly debugged and corrected. Numerical simulation technology enables the simulation of the forming process of sheet metal and prediction of defects in design, thus to improve labor efficiency, save time and reduce costs. In this paper, the software Dynaform is used as a platform and a three-dimensional model is built to numerical simulate and analyze the drawing deep of a typical thin-walled cylindrical piece.Orthogonal experimentis adopted to analyze the impact of BHF, punching speed and punch-die gap on forming quality of the drawing pieces. With minimum thickness and wrinkling as indicators, the impact of various factors is analyzed and a set of optimum parameters is found out that is, BHF is 20kN, punching speed is 2000mm / s and punch-die gap is 0.9mm.

Analysis of OSB Mat Structure Using CAD Technology

2010 ◽  
Vol 113-116 ◽  
pp. 1619-1623
Author(s):  
Peng Li ◽  
Yu Bo Tao ◽  
Feng Hu Wang ◽  
Sun Guo Wang
Keyword(s):  
Computer Aided Design ◽  
Structural Characteristics ◽  
Three Dimensional ◽  
Three Dimensional Model ◽  
Forming Process ◽  
Strand Orientation ◽  
Realistic Description ◽  
Relationship Of ◽  
The Impact ◽  
The Relationship

For further researching the structural characteristics of Orientated strand board (OSB) mat, a three-dimensional model was developed using computer-aided design (CAD) technology to simulate behaviors of individual strands in the mat-forming process. This model provided a more realistic description of the mat structure than the previous simulations in using varied strand geometry and different types of strand orientation, defining strand location, and solving the problem of edge effect. This model can be used to analyze the impact of strand orientation on the number of strand overlaps, and to identify the relationship of strand orientation and the horizontal voids distribution in the mat. Information provided by this model is the basis of further studying the effect of the mat formation on panel void characteristics, and the relationship of the voids volume to panel properties.

CAD Software Development for the Continuous Flexible Forming Process

2011 ◽  
Vol 189-193 ◽  
pp. 2907-2910
Author(s):  
Lin Liu ◽  
Zhong Yi Cai ◽  
Shao Hui Wang ◽  
Mine Zhe Li
Keyword(s):  
Three Dimensional ◽  
Cad Model ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Forming Process ◽  
Flexible Forming ◽  
The Core ◽  
Core Function ◽  
Flexible Forming Process ◽  
The Mathematical Model

The software for the continuous flexible forming process was developed using Visual C++ platform. It can directly read the triangular mesh data of the CAD model. The three-dimensional model was reconstructed rapidly by using the core function of the OpenGL. Moreover, the mathematical model of adjusting the flexible rolls and the longitudinal curvature were established by this software. Using these mathematical descriptions the simulation of the continuous flexible forming process can be finished from the viewpoint of geometry.

scholarly journals Heating and Fusion of A Tungsten Micro Sphere using Powerful Laser Irradiation

2021 ◽  
Vol 3 (1) ◽  
pp. 1-3
Author(s):  
Mihai Oane ◽  
Keyword(s):  
Laser Pulse ◽  
Laser Beam ◽  
Laser Irradiation ◽  
Small Dimension ◽  
Intense Laser ◽  
Pulse Interval ◽  
Heating Source ◽  
Order Of Magnitude ◽  
Two Stages ◽  
Micro Sphere

The intense laser irradiation of a micro/nano size W sphere sample is considered in the present paper. Like numerical example, we choose a sphere with a radius of 1 µm. The present article’s point consists of approximating that the target’s temperature homogenization time is of the same order of magnitude as the first laser pulse duration. Our model is valid in the radius limits: 10 nm to 10 µm. We consider like heating source a laser beam with YAG/Nd:YAG/ Cr4+:YAG composite crystal. The nature of the interaction between a laser beam and small dimension tungsten (W) sample is of great importance for both theoretical and experimental perspectives. In principle, we have three stages: i) laser- W bulk interaction; ii) plasma formation, heating, and iii) adiabatic expansion. In the present paper, we will focus on the first two stages of laser pulse interval.

Stability Analysis on the Roof Trusses of the Broumov Group of Churches to Underline Statical Sense of Dientzenhofers

2010 ◽  
Vol 133-134 ◽  
pp. 385-390 ◽  
Author(s):  
Pavel Kuklík ◽  
Peter Duinker ◽  
Justin Hettinga
Keyword(s):  
18Th Century ◽  
Three Dimensional ◽  
Order Theory ◽  
Material Strength ◽  
Three Dimensional Model ◽  
Finite Element Software ◽  
Structural Capacity ◽  
Identification Of Fungi ◽  
Three Dimensional Models ◽  
The Stability

The Broumov group of churches represents an integral part of Bohemian baroque architecture. The famous Dientzenhofer family of architects, that helped define the Bohemian baroque style in the early 18th century, designed the Broumov group for the governing Benedictine abbey of St. Wenceslaw in Broumov. This report summarizes a structural investigation, using FIN10 finite element software, into the stability and efficiency of the roof trusses design. The structures age and current state were taken into account in calculating both the applied loads and structural capacity by increasing loads and reducing material strength. A damage analysis, including identification of fungi species, was performed, documented and implemented in a three-dimensional model for comparison with undamaged results. Magnitude and distribution of axial and bending forces were determined using both two dimensional and three-dimensional models for several load cases. Using the comparison of 1st order and 2nd order structural analysis results and Eurocode specified criteria, critical and unnecessary members of the roof system were identified and evaluated. Classical linear elastic 2nd order theory was used based of Eulerian principles, ignoring geometrical non-linearity and non-linear material effects. The main analysis was performed on the St. Ann church in Viznov and St. Barbora church in Otovice.

scholarly journals Thermal Behavior of Cylindrical Buckling Restrained Braces at Elevated Temperatures

2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Elnaz Talebi ◽  
Mahmood Md. Tahir ◽  
Farshad Zahmatkesh ◽  
Airil Yasreen ◽  
Jahangir Mirza
Keyword(s):  
Elevated Temperatures ◽  
Three Dimensional ◽  
Circular Cross Section ◽  
Material Strength ◽  
Three Dimensional Model ◽  
Steel Core ◽  
Linear Behavior ◽  
Cylindrical Steel ◽  
Primary Focus ◽  
Brb System

The primary focus of this investigation was to analyze sequentially coupled nonlinear thermal stress, using a three-dimensional model. It was meant to shed light on the behavior of Buckling Restraint Brace (BRB) elements with circular cross section, at elevated temperature. Such bracing systems were comprised of a cylindrical steel core encased in a strong concrete-filled steel hollow casing. A debonding agent was rubbed on the core’s surface to avoid shear stress transition to the restraining system. The numerical model was verified by the analytical solutions developed by the other researchers. Performance of BRB system under seismic loading at ambient temperature has been well documented. However, its performance in case of fire has yet to be explored. This study showed that the failure of brace may be attributed to material strength reduction and high compressive forces, both due to temperature rise. Furthermore, limiting temperatures in the linear behavior of steel casing and concrete in BRB element for both numerical and analytical simulations were about 196°C and 225°C, respectively. Finally it is concluded that the performance of BRB at elevated temperatures was the same as that seen at room temperature; that is, the steel core yields prior to the restraining system.

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